JP2009-208526A discloses a roof opening/closing control device for a wing vehicle, which opens and closes left and right roofs of a wing vehicle using a hydraulic cylinder. In the roof opening/closing control device disclosed in JP2009-208526A, a rotation speed of a motor is controlled on the basis of information indicating a roof angle, whereupon an amount of working oil supplied to the hydraulic cylinder is controlled. In the roof opening/closing device disclosed in JP2009-208526A, roof opening/closing operations can be started and stopped gently by controlling the amount of working oil supplied to the hydraulic cylinder.